A very instructive story:
In 1944, 29 reindeer were left on the uninhabited St. Matthew Island. Mosses and lichens, the main food of reindeer, were excellent. The thickness of the moss reached 10 cm. There were no predators or hunters on the island, and the number of animals over the next 19 years increased at a rate of 32% per year, reaching 6,000 heads in 1963.
Over the next three years, almost all animals died out, leaving a pathetic herd of 41 female reindeer and one male. In the snowy winter of 1963-1964, the weather was not severe enough to prevent reaching food. The reason was different: overgrazing, extreme depletion of the pasture.
The carrying capacity of a territory is defined as the maximum number of animals that can be supported over a year without damaging the environment. For St. Matthew Island, it is 5 reindeer per 1 sq. km. This value was reached already in 1957 with a herd size of 1,350 heads. During the population peak, there were 18 individuals per 1 sq. km.
After that, the livestock grew for some time, while the reproducibility of food decreased. Degradation of the pasture turned out to be irreversible; a sharp jump-like decrease in the reindeer population occurred. After the collapse, there were only 0.126 animals per 1 sq. km., but for the depleted pasture even this turned out to be too much.
Restoration of the pasture even in the complete absence of animals takes decades. In the presence of the remaining herd, it became impossible: the carrying capacity of the island decreased by at least 97.5%.
I think many people should familiarize themselves with the results of these observations.
